{
 "version": "2026-10-20",
 "license": "Dimension sheets are written by Xem Studio from the cited sources and are free to use (CC BY 4.0, attribute 'Xem Studio'). Linked files belong to their publishers under the license shown; Xem Studio does not host them. 'license_verified: false' means the license shown is from memory or the publisher's page as last read and should be confirmed at the link before commercial use.",
 "slug": "fluidyne-manifold-half-inch",
 "name": "Fluidyne manifold for 1/2 in copper U-tube legs",
 "kind": "hardware",
 "category": "Stirling engines",
 "group": "Thermoacoustic & fluidyne",
 "year": null,
 "question": "What joins the two legs of a fluidyne liquid-piston Stirling engine?",
 "tags": [
  "fluidyne",
  "liquid piston",
  "manifold",
  "stirling",
  "long earth society"
 ],
 "aliases": [
  "fluidyne engine",
  "fluidyne manifold",
  "liquid piston stirling engine",
  "west fluidyne"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": true,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/fluidyne-manifold-half-inch/",
 "sheet_txt": "https://xemstudio.com/objects/fluidyne-manifold-half-inch/sheet.txt",
 "sheet": {
  "basis": "West's fluidyne; sockets at 1/2 in copper tube OD Ø15.88 (fit: socket); port at the 4 mm OD tube",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "The top of the fluidyne's displacer U-tube: a 90 × 24 × 24 block with 4 mm vertical-edge radii.",
   "An 8 × 8 gas passage 60 long joins the gas spaces above them.",
   "A Ø4 port from the passage out through one side takes the 4 mm tuning line (fit: press), which sets the phase."
  ],
  "table": {
   "columns": [
    "parameter",
    "value"
   ],
   "rows": [
    [
     "block",
     "90 × 24 × 24"
    ],
    [
     "sockets",
     "2 × Ø15.88 × 16, 60 apart"
    ],
    [
     "gas passage",
     "8 × 8 × 60"
    ],
    [
     "tuning port",
     "Ø4"
    ]
   ]
  }
 },
 "sheet_text": "Fluidyne manifold for 1/2 in copper U-tube legs — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/fluidyne-manifold-half-inch/  (CC BY 4.0)\nBasis: West's fluidyne; sockets at 1/2 in copper tube OD Ø15.88 (fit: socket); port at the 4 mm OD tube\nCatalog version: 2026-10-20\n\nSizes: see table below\n- The top of the fluidyne's displacer U-tube: a 90 × 24 × 24 block with 4 mm vertical-edge radii.\n- An 8 × 8 gas passage 60 long joins the gas spaces above them.\n- A Ø4 port from the passage out through one side takes the 4 mm tuning line (fit: press), which sets the phase.\n\nparameter  value\nblock  90 × 24 × 24\nsockets  2 × Ø15.88 × 16, 60 apart\ngas passage  8 × 8 × 60\ntuning port  Ø4\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Wikipedia: Fluidyne engine — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Fluidyne\n- C. D. West: Liquid Piston Stirling Engines (1983) — book, reports (OSTI) — reference / US Gov reports public domain [verify license at link] — https://www.osti.gov/search/semantic:fluidyne\n- Long Earth Society: Engine builds — web, video — LES site — https://longearthsociety.com/engineering/\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/fluidyne-manifold-half-inch/index.json\nAPI: https://xemstudio.com/api/geometry?object=fluidyne-manifold-half-inch\n",
 "sources": [
  {
   "publisher": "Wikipedia",
   "title": "Fluidyne engine",
   "url": "https://en.wikipedia.org/wiki/Fluidyne",
   "formats": [
    "web"
   ],
   "license": "CC BY-SA 4.0 (text)",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "C. D. West",
   "title": "Liquid Piston Stirling Engines (1983)",
   "url": "https://www.osti.gov/search/semantic:fluidyne",
   "formats": [
    "book",
    "reports (OSTI)"
   ],
   "license": "reference / US Gov reports public domain",
   "license_verified": false,
   "hosted": false
  },
  {
   "publisher": "Long Earth Society",
   "title": "Engine builds",
   "url": "https://longearthsociety.com/engineering/",
   "formats": [
    "web",
    "video"
   ],
   "license": "LES site",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "fluidyne-output-tee",
  "copper-pipe-type-l-m",
  "silicone-tube",
  "thermoacoustic-heat-exchanger",
  "stirling-configurations-guide"
 ],
 "fits": [
  {
   "role": "Goes in or on",
   "items": [
    {
     "slug": "copper-pipe-type-l-m",
     "why": "1/2 in legs in the Ø15.88 sockets"
    }
   ]
  },
  {
   "role": "Connects to",
   "items": [
    {
     "slug": "silicone-tube",
     "why": "4 mm tuning line in the Ø4 port"
    },
    {
     "slug": "fluidyne-output-tee",
     "why": "tuning line to the output column"
    }
   ]
  },
  {
   "role": "Alternatives",
   "items": [
    {
     "slug": "borosilicate-test-tubes",
     "why": "glass leg"
    }
   ]
  }
 ],
 "dimensions": "exact (nominal, no printing tolerance)",
 "dimension_rule": "All geometry on Xem Studio is exact (nominal, true size) with no printing tolerance. Where a part meets another part, the object lists its mating features (feature, exact size, what it mates with, fit class: press, slide, run, socket, clamp or designed). Apply your process's allowance to those features only; 'designed' gaps are part of the design and stay as drawn.",
 "mating": [
  {
   "feature": "leg sockets",
   "exact": "Ø15.88",
   "mates": "1/2 in copper tube OD",
   "fit": "socket",
   "files": "all"
  },
  {
   "feature": "tuning / side port",
   "exact": "Ø4",
   "mates": "4 mm OD tube",
   "fit": "press",
   "files": "all"
  }
 ],
 "fit_classes": {
  "press": "stays put: pin, tube, bearing or magnet held by interference. Typical FDM: hole +0.0 to +0.1 mm on diameter.",
  "slide": "assembles by hand and is held by a grub, pinch or clamp: shaft in a hub, rod in a socket, spigot in a bore. Typical FDM: +0.2 mm.",
  "run": "turns or slides in use: pin in a link, rod through a guide. Typical FDM: +0.3 mm.",
  "socket": "large sliding fit: syringe barrel, sleeve, bobbin in a bore. Typical FDM: +0.3 mm.",
  "clamp": "split part that closes on the mating part with screws: make it at size.",
  "designed": "a gap that is part of the design (piston fit option, displacer gap, air gap): do not change."
 },
 "faq": [
  {
   "q": "What tube size for a fluidyne?",
   "a": "The manifold sockets are Ø15.88."
  },
  {
   "q": "What sets a fluidyne's frequency?",
   "a": "The U-tube's natural period T = 2π√(L/2g): a 400 mm water column gives about 1.1 Hz."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "fluidyne-manifold-2x-1-2in-copper",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/fluidyne-manifold/fluidyne-manifold-2x-1-2in-copper.step",
   "stl": "https://xemstudio.com/files/hardware/fluidyne-manifold/fluidyne-manifold-2x-1-2in-copper.stl",
   "note": "fluidyne displacer manifold: two Ø15.88 sockets 60 mm apart joined by a gas passage, Ø4 tuning port for 4 mm OD tube"
  }
 ],
 "markdown": "https://xemstudio.com/objects/fluidyne-manifold-half-inch/index.md"
}